Medical image electronics have used a transmission method using a cable to transmit a detected analog signal. However, an increase in a cable length is essentially involved for remote transmission, and therefore a distortion phenomenon of a detected analog output signal occurs and a reduction in performance occurs. To correct the occurrence of the reduction in performance, a method for amplifying a signal using a signal amplification circuit or a method for correcting a signal via an analog/digital converter by a digital signal processing unit has been used. A combination of positron emission tomography (PET) and magnetic resonance imaging (MRI) among medical image electronics may reduce a data acquisition time without additional radiographic exposure to provide in vivo biological information and simultaneously obtain functional and structural images. Thanks to these advantages, the importance of a PET-MRI convergence system is being emphasized. To increase compatibility of the MRI and the PET, a study on the PET-MRI convergence system using a semiconductor sensor as an alternative plan of a photomultiplier has been actively progressed.
Meanwhile, to design the PET-MRI convergence system, various signal transmission methods have been researched. First, a method for positioning only a scintillation crystal within an MR-bore and transmitting light from the scintillation crystal to the PMT via an optical fiber has a problem in that PET performance such as energy resolution and time resolution may be reduced and a volume of the optical fiber may be increased.
Second, there is a method for positioning a PET detection module, which is configured to include a scintillation crystal, a photo-sensor, and a preamplifier, within the MR-bore and transmitting an amplified signal from the preamplifier to the ADC via a voltage transmission cable. The method has a problem in that a space limitation may occur due to a front-end electronics positioned within the MR-bore, a shielding technology like shielding the PET detection module with copper to protect the PET detection module from a magnetic field may be required, and the reduction in the PET performance and the distortion of the MRI image may occur due to heat generated from the preamplifier.